Cloudformation is spot on. There is simply no excuse in 2020 to use it when cloud agnostic Terraform exists.

Elasticache is expensive and the analysis is generally correct on that, however if you do actually need a high capacity rock solid Redis cluster and you can afford it, it does the job. Paying someone to setup and scale a cluster of that magnitude would probably cost a year's worth of usage. Of course if you don't actually need to scale it yet then just use the suggestions in the article to run it yourself.